What type bottle is this?

[SargeEMS]

So it's basically a paperweight in the US? Thanks a lot for the responses.

 

[runsongas]

if you have your own fill station and are confident it is safe to fill (get a hydro without a stamp and then vis it yourself), you can certainly fill and use it yourself. dive shops won't touch it though.

 

[runsongas]

As an air gun charging cylinder with that "surface only" valve fitted you get 5 years use before hydro (UK and EU use) For diving conversion you add a diving DIN valve £30 and another £30 for the hydro. you get same 5 year hydro but have to add additional periodic visual inspections for submerged use. Hence It's worth nothing for diving. As you dont say where you are from and as it is a UK/EU cylinder set for air gun filling I have assumed your in the EU/UK
Scubaboard is an American forum you will get an American centric reply hence the DOT Dept of Transportation advise and my question regarding your location.

I should add if you are in USA and in addition to the earlier advise that the American DOT federal requirement would be required, As the cylinder was built for a European standard with a M25x 2 thread form metric. The typical Amercan thread form is 3/4 NPSM they dont mix and should never be mixed up.

how is it worth nothing for diving in the EU? a new valve and hydro is still cheaper than buying a new cylinder

 

[iain/hsm]

how is it worth nothing for diving in the EU? a new valve and hydro is still cheaper than buying a new cylinder

It’s not that easy, first your right your cylinder does have a value but only to an air gunner. From a divers point of view, you can pay more for a hamburger than that untested 3 litre cylinder bare is worth, so a value yes but not much.

Second the cost to convert it with a diving valve and hydro for diving is a worthless exercise for two reasons.

1. No one dives scuba with a 3 litre 300 bar “pony” anymore
2. No one with a rebreather would need 300 bar

For a 300 bar 3 litre volume what’s the point, The heavy weight is against you the narrow diameter and corresponding longer length to make the volume is against you and the fact it was originally intended for air gun use (if used) internally adds two additional risks for any diver to consider.

Paint ball and air gunners don’t usually worry too much about a minus 60 C dewpoint or dry gas for breathing air in the tank so these cylinders tend to have more internal corrosion, and if you see the junk from China they use to fill them with you would understand the additional risk. And if that wasn’t enough add a shotblast and oxygen clean to your bill, Frankly I would choose the hamburger.

 

[Subcooled]

If you own your compressor, then you don't need official stamps. You just need to test the cylinder. Getting test results is one thing, getting approval stamps is another. The comment above (airguns and internal rust) is worth to notice, though.